Residual stress in wire and arc additively manufactured aluminum components

Abstract

In this study, a number of numerical simulations have been performed to analyze the distribution characteristics of residual stress (RS) in the wire and arc additive manufacturing (WAAM) components made of aluminum alloys. Experiments have been performed to measure temperature results (thermal cycles, etc.), residual stresses, and deformation for verification. The results show that the variation in the height of beam can affect the magnitude and distribution of longitudinal RS in both the substrate and the beam, while that can only influence the transverse RS in the substrate but not in the beam nearly. The longitudinal RS on the top surface of the last layer in the WAAM parts changes from tension to compression if the height of beam is above a certain value (about 20 mm here), which is obviously different from that in the multi-pass weldments and the selective laser melting (SLM) components. The restraint condition of the substrate can apparently affect the magnitude and distribution of longitudinal RS in the beam, while that almost has no influence on transverse RS in the beam. In terms of numerical results, the generation mechanism and distribution of RS in WAAM components have been systematically illuminated in the current work, which is quite useful to guide the mitigation of the generated high RS.